Method of producing a touch panel

ABSTRACT

First, a display panel having a pixel region and a controlling circuit region is formed. Then a plurality of pixels arranged in array is formed in the pixel region. A plurality of orientation patterns that do not overlap the pixels is formed. Finally an input device is provided. The input device has a sensor adapted to detect the orientation patterns and generates at least a signal adapted to input data.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 10/708,376 filedon Feb. 27, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of producing a touch panel,and more particularly, to a method of forming a plurality of orientationpatterns on a display panel.

2. Description of the Prior Art

Since portable information products, such as PDAs, mobile phones,notebooks, and tablet PCs are more and more prevailing, touch panels arebroadly applied to these products as an input interface. Especially whenrequirements of tablet PCs rise, the touch panel becomes one of the mostimportant components because it integrates the input functions with theoutput functions in the same interface (display).

Touch panels are mainly classified into four types: resistance type,capacitor type, supersonic type, and optic type, wherein the resistancetype touch panel is most widely used because of its lower cost andthinner thickness. Refer to FIG. 1, which is a schematic diagram of aprior art resistance type touch panel 10. As shown in FIG. 1, the priorart resistance type touch panel 10 includes an ITO glass 12, a bottomITO film 14, a top ITO film 16, a plurality of dot spacers 18 arrangedin an array between the bottom ITO film 14 and the top ITO film 16, anda PET (polyethylene terephthalate) layer 20. The resistance type touchpanel 10 is positioned on a display panel (not shown). When a user usesan input tool (such as finger or pen) to press the PET layer 20,corresponding voltages will be generated between the top ITO film 16 andthe bottom ITO film 14 via the dot spacers 18. Then coordinates of theinput tool tracks will be generated and transferred to a processor (notshown) via conductive wires (not shown) laid under the bottom ITO film14. Finally corresponding signals will be generated and transferred tothe display panel.

Although resistance type touch panels are most widely used so far, theresistance type touch panel has some shortcomings, such as poor apertureratio, low durability, and poor input accuracy. Among all theabove-mentioned problems, the input accuracy is a critical issue forusers to consider when choosing a touch panel. When a user uses a pen towrite data on the touch panel, the pen tip will naturally leave thesurface of the touch panel. This action reduces the pressure applied tothe resistance type touch panel and further reduces the correspondingvoltages, such that input errors will happen. Furthermore, the user'spalm will easily contact the touch panel when writing data, and thiswould also generate input errors. In addition, the resistance type touchpanel is assembled by glue, thus the border area of the touch panel isfull of glue. This makes the user have to depress the touch panel harderto input data in the border area than in the central area.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a methodof producing a touch panel to solve the above-mentioned problems.

The present invention provides a method of producing a touch panel. Themethod includes: providing a display panel having a pixel region and acontrolling circuit region; forming a plurality of pixels arranged in anarray in the pixel region adapted to display images; forming a pluralityof orientation patterns in the pixel region adapted to designatecoordinates of the pixel region; and providing an input device adaptedto input data; wherein the input device includes a sensor adapted todetect orientation patterns, and the orientation patterns arefluorescent patterns or magnetic patterns.

It is an advantage of the present invention that a sensor is employed todetect the orientation patterns, such that the coordinates of the inputpoints are accurately recognized. In addition, the orientation patternsdo not overlap the pixels, thus the poor aperture ratio problem of theprior art resistance type touch panel is avoided.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a prior art resistance type touchpanel.

FIG. 2 is a schematic diagram of a touch panel of the present invention.

FIG. 3 is a top view of the touch panel illustrated in FIG. 2.

FIG. 4-6 are schematic diagrams illustrating a method of producing thetouch panel according to the first embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a method of producing thetouch panel according to the second embodiment.

FIG. 8-10 are schematic diagrams illustrating a method of producing thetouch panel according to the third embodiment.

DETAILED DESCRIPTION

Refer to FIG. 2, which is a schematic diagram of a touch panel 30 of thepresent invention. As shown in FIG. 2, the touch panel 30 includes adisplay panel 32, a plurality of orientation patterns 34, and an inputdevice 36. The display panel 32 further includes a pixel region (notshown) and a controlling circuit region (not shown). The pixel regionincludes a plurality of pixels arranged in an array for displayingimages. The controlling region includes a controlling circuit fordriving the pixels. The display panel 32 is a flat display panel, suchas an LCD panel, a top emission OLED display panel, a bottom emissionOLED display panel, a plasma display panel, or a non-flat display panel.The input device 36 has a sensor including a light emitting element 38and a light sensor 40.

In the present invention, the light emitting element 38, such as an LED,is used for emitting a light with a specific wavelength to theorientation patterns 34, and the light sensor 40, such as acharged-couple device (CCD), is used for detecting and receivingcoordinates representing the orientation patterns 34. Therefore when auser uses the input device 36 to input data, the light sensor 40 willreceive the coordinates of the tracks, generate at least a correspondingsignal, and transfer the signal to the display panel 32 via a processor(not shown).

Refer to FIG. 3, which is a top view of the touch panel 32 shown in FIG.2. As shown in FIG. 3, the orientation patterns 34 are positioned on thedisplay panel 32 but do not overlap the pixels 33, thus the apertureratio is not reduced. It is worth noticing that the orientation patterns34 are composed of fluorescent inks including anthracene or aromaticcompounds, thus the orientation patterns 34 are not visible unless theinput device 36 irradiates a light with a specific wavelength to theorientation patterns 34. Alternatively, the orientation patterns 34 canbe composed of magnetic inks. In this case, a magnetic sensor mustreplace the sensor of the input device 36 for detecting the orientationpatterns 34 and generating corresponding signals.

Refer to FIG. 4-6, which are schematic diagrams illustrating a method ofproducing the touch panel according to the first embodiment of thepresent invention. As shown in FIG. 4, a display panel 50 is provided,and a halftone 52 is positioned on the display panel 50. As shown inFIG. 5, then a chemical aid 54 is coated on the halftone 52 to form theorientation patterns. Finally as shown in FIG. 6, the halftone 52 isremoved to accomplish the touch panel of the present invention.

Refer to FIG. 7, which is a schematic diagram illustrating a method ofproducing the touch panel according to the second embodiment. As shownin FIG. 7, first a display panel 50 is provided, and then an ink jethead 60 is employed to spray the chemical aid 54 on the display panelfor forming the orientation patterns. The chemical aid 54 is afluorescent ink, a magnetic ink, or a solution including fluorescent ormagnetic substances.

Refer to FIG. 8-10, which are schematic diagrams illustrating a methodof producing the touch panel according to the third embodiment. As shownin FIG. 8, a display panel 50 is provided, and a chemical aid 54 iscoated on the display panel 50 to form a photosensitive film. Thephotosensitive film is composed of photosensitive fluorescent ink orphotosensitive magnetic ink, and formed by spin coating or bladecoating. As shown in FIG. 9, a photolithography process is performed bya mask 62 to transfer the orientation patterns on the display panel 50.As shown in FIG. 10, finally a development process is performed toremove excessive chemical aid 54. It is worth noticing that if theorientation patterns are composed of non-photosensitive magnetic ink,then a photo resist layer must be deposited on the display panel 50before the photolithography process to transfer the orientationpatterns.

In summary, the method of the present invention forms a plurality oforientation patterns which do not overlap the pixel region of thedisplay panel, and utilizes the sensor of the input device to receivethe coordinates representing the orientation patterns, thus the apertureratio of the display panel is remained. Furthermore, the sensor of theinput device 36 can be a photosensitive sensor, a magnetic sensor, anelectronic sensor, or other type sensors. The data of the orientationpatterns 34 representing different coordinates can be stored in theprocessor or the display panel. However, that is not the scope of thepresent invention, thus unnecessary detail is not disclosed here.

In addition, the orientation patterns can be formed in different typedisplay panels, such as an LCD panel or OLED display panel. Also, theorientation patterns are not limited to be formed on the surface of thedisplay panel. For example, if an LCD display is used, the orientationpatterns can be formed on the surface of the LCD panel, or between thetop substrate and the black matrix layer. If a top emission OLED displaypanel is used, the orientation patterns can be formed on the top surfaceof the glass container or on the bottom surface of the glass container.If a bottom emission OLED display panel is used, the orientationpatterns can be formed on the bottom surface of the bottom substrate orbetween the thin film transistors and the bottom substrate.

Compared to the prior art, the present invention forms a plurality oforientation patterns on the display panel which do not overlap thepixels, and utilizes the sensor of the input device to detect andreceive the orientation patterns. Therefore, the input accuracy isimproved while the aperture ratio is remained.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

1. A method of producing a touch panel comprising: providing a displaypanel which comprises a pixel region and a controlling circuit region;forming a plurality of pixels arranged in an array in the pixel regionadapted to display images; forming a plurality of magnetic patterns notoverlapping the pixels in the pixel region adapted to designatecoordinates of the pixel region; and providing an input device adaptedto input data, the input device comprising a magnetic sensor adapted todetect and the magnetic patterns.
 2. The method of claim 1, wherein themagnetic patterns are formed by halftone printing or ink jet printing.3. The method of claim 1, wherein the method of forming the magneticpatterns further comprises: forming a photosensitive film on the displaypanel; performing an exposure process by a mask; and performing adevelopment process to form a plurality of magnetic patterns notoverlapping the pixels; wherein the photosensitive film is aphotosensitive magnetic ink, and the photosensitive film is formed byspin coating or blade coating.
 4. The method of claim 1, wherein thedisplay panel is an LCD panel, and the magnetic patterns are formed on atop substrate surface of the LCD panel or between the top substrate anda black matrix layer.
 5. The method of claim 1, wherein the display is atop emission OLED display panel having a glass container, and themagnetic patterns are positioned on a top surface of the glass containeror on a bottom surface of the glass container.
 6. The method of claim 1,wherein the display panel is a bottom emission OLED display panel havinga bottom substrate and a plurality of thin film transistors, and themagnetic patterns are positioned on a bottom surface of the bottomsubstrate or between the bottom substrate and the thin film transistors.7. The method of claim 1, wherein the controlling circuit region furthercomprises a controlling circuit adapted to drive the pixels, and thetouch panel further comprises a processor adapted to receive the signalsfrom the sensor and to drive the controlling circuit to display tracksof the input device.